Foliar uptake,translocation and metabolism of a novel experimental ‘phosphonamidate’ herbicide in Setaria viridis and Abutilon theophrasti     

Jenny A. Wiesendanger  David W. Bartlett  Eric D. Clarke  Michael D. Broadhurst 《Pest management science》1995,44(1):75-77

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A comparison of production and management between Wisconsin organic and conventional dairy herds     

K. Sato  P.C. Bartlett  R.J. Erskine  J.B. Kaneene 《Livestock Production Science》2005,93(2):105-115

An observational study was conducted in Wisconsin to compare production and management on organic and conventional dairy farms. Thirty organic dairy herds, where antimicrobials are rarely used for calves and never used for cows, were compared with 30 neighboring conventional dairy farms on which antimicrobials were routinely used for animals of all ages. A seven-page questionnaire regarding milk production, milking practices, housing, incidence of the major dairy diseases and medical treatments was used to assess management and production during 2000-2001. Body condition scores (BCS) of lactating cows and environmental and animal sanitation scores (EASS) were also collected on each of two occasions. The organic herds had significantly fewer cattle than did the conventional herds (P=0.017). The average daily milk production per cow in organic dairy herds (20.2 kg/day) was lower than that of conventional herds (23.7 kg/day). The incidence of clinical mastitis (CM) on organic farms (28 cases per 100 cow-years at risk) was not statistically different from that of on conventional farms (32 cases per 100 cow-years at risk). No significant difference in bulk tank somatic cell count (BTSCC) was observed between organic farms (262,000 cells/ml) and conventional farms (285,000 cells/ml). The average annual cull rate was 18.0 cases per 100 cow-years for the conventional farms and 17.2 for the organic farms (P=0.426). Our paired t-test results indicated significantly higher parasite burden on organic dairy farms; however, no significant difference between the two farm types when controlling for season (March and September), grazing intensity (no grazing, little grazing, grazing with access to housing and grazing only) and herd average milk production per cow. There was little evidence of other fundamental differences between the two farm types in other management and production parameters.  相似文献   

Diptacus swensoni Keifer (Acari: Rhyncaphytoptidae) Infesting Holly in England.     

C E. Bowman  P. W. Bartlett 《Plant pathology》1978,27(4):202-202

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Honey Bees (Apis mellifera Hymenoptera: Apidae) Preferentially Avoid Sugar Solutions Supplemented with Field-Relevant Concentrations of Hydrogen Peroxide Despite High Tolerance Limits     

Lewis J Bartlett  Carlos Martinez-Mejia  Keith S Delaplane 《Journal of insect science (Online)》2022,22(1)

Honey bees (Apis mellifera L. Hymeoptera: Apidae) use hydrogen peroxide (synthesized by excreted glucose oxidase) as an important component of social immunity. However, both tolerance of hydrogen peroxide and the production of glucose oxidase in honey is costly. Hydrogen peroxide may also be encountered by honey bees at high concentrations in nectar while foraging, however despite its presence both in their foraged and stored foods, it is unclear if and how bees monitor concentrations of, and their behavioral responses to, hydrogen peroxide. The costs of glucose oxidase production and the presence of hydrogen peroxide in both nectar and honey suggest hypotheses that honey bees preferentially forage on hydrogen peroxide supplemented feed syrups at certain concentrations, and avoid feed syrups supplemented with hydrogen peroxide at concentrations above some tolerance threshold. We test these hypotheses and find that, counter to expectation, honey bees avoid glucose solutions supplemented with field-relevant hydrogen peroxide concentrations and either avoid or don’t differentiate supplemented sucrose solutions when given choice assays. This is despite honey bees showing high tolerance for hydrogen peroxide in feed solutions, with no elevated mortality until concentrations of hydrogen peroxide exceed 1% (v/v) in solution, with survival apparent even at concentrations up to 10%. The behavioral interaction of honey bees with hydrogen peroxide during both within-colony synthesis in honey and when foraging on nectar therefore likely relies on interactions with other indicator molecules, and maybe constrained evolutionarily in its plasticity, representing a constitutive immune mechanism.  相似文献   

Apparent Visible Violet Radiation in the Recent Large Sunspot Group     

Bartlett JC 《Science (New York, N.Y.)》1946,103(2684):681-682

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Managerial risk factors of intramammary infection with Streptococcus agalactiae in dairy herds in Ohio.     

P C Bartlett  G Y Miller  S E Lance  D D Hancock  L E Heider 《American journal of veterinary research》1992,53(9):1715-1721

Dairy herds in Ohio were selected by stratified random sampling for participation in a disease-monitoring study to relate Streptococcus agalactiae intramammary prevalence to herd management and environmental conditions. Of 48 herds studied, 27 herds had at least 1 cow infected with this pathogen. Management and environmental conditions were assessed by direct observation as well as by an interview with the dairy producers. One-way ANOVA or chi 2 analysis, with presence or absence of Streptococcus agalactiae as the dependent variable, was used to test each of 70 independent variables. Variables found significant at P less than 0.20 were further evaluated by use of logistic regression. Our sample size permitted only 4 independent variables to be simultaneously evaluated by logistic regression. The most predictive risk factors were identified as poor teat and udder hygiene, poor environmental sanitation, large herd population, and use of a shared washcloth for premilking cleaning of teats and udders.  相似文献   

Herbicidal indolizine-5,8-diones: photosystem I redox mediators     

Smith SC  Clarke ED  Ridley SM  Bartlett D  Greenhow DT  Glithro H  Klong AY  Mitchell G  Mullier GW 《Pest management science》2005,61(1):16-24

6,7-Disubstituted indolizine-5,8-diones showed activity as herbicides, giving rapid desiccation symptomology in whole-plant tests and bleaching in leaf-disc assays. In isolated chloroplasts, such compounds initiated rapid uptake of oxygen in Photosystem I. A redox mediator mode of action was further supported by electrochemical studies. Several compounds described had low photostability, high volatility, hydrolytic instability or reactivity with glutathione. The detrimental effects that these factors may have had on expression of herbicidal activity are discussed.  相似文献   

Carbonate sediments: oriented lithified samples from the north atlantic     

Bartlett GA  Greggs RG 《Science (New York, N.Y.)》1969,166(3906):740-741

Indurated carbonate samples, obtained from the North Atlantic sea floor with a deep-sea drill coring apparatus, suggest that the phenomenon of deep-sea carbonate lithification is more complex than had been thought previously. Lithified-nonlithified couplets can now be related in age and orientation. Age determinations based on the method of carbon-14 dating show that adjacent nonlithified-lithified layers may differ in age by more than 30,000 years.  相似文献   

Bridged Carbonium Ions from Different Sources     

Bartlett PD  Closson WD  Cogdell TJ 《Science (New York, N.Y.)》1963,140(3565):378

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Penstrep clarification     

Bartlett P 《Australian veterinary journal》2000,78(6):381-381

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